1. Field of the Invention
The invention is directed to a knife having a series of longitudinally arranged circular breakage holes defining transverse breakage zones.
2. Description of the Prior Art
Reciprocating sickle bar mowers are used to cut vegetation and crops. A plurality of knives are mounted to the sickle bar by mounting bolts or rivets. The sickle bar reciprocates in a channel defined by sickle bar guards. The guards have slots in which the knives reciprocate. The edges of the slots are provided with ledger plates that cooperate with the reciprocating knives to cut the crop and vegetation by a scissors-like action. Each knife is provided with a base portion extending in the transverse direction and knife portion extending longitudinally out from the base portion. The base portion is provided with mounting holes for receiving the mounting rivets or bolts. The knife portion in turn is triangular in shape and is provided with two cutting edges. Adjacent knives maybe integrally joined together to form double knife sections. Some knives have holes to better clean out debris from between the knife and the knife guard.
It is an object of the present invention to provide a knife for a reciprocating sickle bar mower having defined transverse breakage zones wherein a knife breaks along one of these transverse breakage zones when a stone or other foreign object is trapped between the reciprocating knife and the guard.
It is another object of the present invention to provide a knife that can still function even though it is broken at one of the transverse breakage zones.
It is a feature of the present invention that the knives are through hardened which prevents them from bending when contacting stones and other foreign objects.
A double knife section for a reciprocating sickle bar mower is provided with two knives. Each knife is provided with a base portion extending in the transverse direction and a knife portion extending in the longitudinal direction. The base portion is provided with at least two mounting holes. The knife portion is provided with two cutting edges. The knife is also provided with a series of breakage holes defining transverse breakage zones which allow a knife to break before damaging the knife guard when the knife contacts a stone or other foreign object.